AI engineering is about building real systems around the model, not just calling it. It covers agents, harnesses, tools, memory, and the whole infrastructure that turns a probabilistic LLM into something reliable enough to act on its own.
More memory can quietly make an agent worse. Here are the six layers of agent memory that actually work, and why deliberate forgetting matters.
Your model is a genius with no hands. Harness engineering is how you give it a body, and the thing that actually makes an AI agent reliable.